Hi Jon,

Thanks for your reply. The location is Rutland, in the centre of England. My parents' cottage is also a dwelling place for an active community of honey bees which live in a hole in the wall, and which have produced two swarms this year, to the delight of local bee keepers. Perhaps this little nest is their work? I have attached a bit of video to show more aspects of it.

I should add that the nest feels waxy, but has no discernable smell or taste.

If it is in what I think it is, it is a rather unusual picture. It would be helpful to see what it looks like from the side, in particular how it is attached to the branch. It would be even more helpful to know where you are writing from. I admit though, that the probable builder is a member of a large and fairly variable group and that species from various parts of the world differ considerably, both in their appearance and in the appearance of their nests.

Firstly, it is a wasp nest. Mike got that right in one.

Secondly, it is a wasp nest made of paper.

Thirdly, it is almost certainly the first nest constructed by a young queen trying to establish a new colony.

About there I run out of steam.

For one thing, I do not recognise that nest shape. It looks almost like a bee comb, being so clean, but it also looks as though it is one-sided, whereas bee combs are double sided.

It is so clean that it looks as though it is made of wax, which also would indicate a bee construction, but the more closely I look, the more it looks like a clean, new, paper construction.

Now, paper wasps (omitting a small group irrelevant to this question) are all in the family Vespidae. They include the hornets and yellowjackets in one major subfamily, and the polistine paper wasps in another major subfamily. There are some other minor groups, but this picture does not suggest any of them to me.

Once a colony is well established the nest tends to get pretty heavily used, turning a dirty grey, which makes it less conspicuous, so that is no disadvantage.

However, young queens starting out on their own tend to make the nests laboriously from new material, which tends to be light in colour, though if you examine the picture carefully, you can see the first signs of dirt collecting on those nice clean cells.

The further you live from the equator, the more strongly I should guess that to be the nest of a Vespinid, whereas the warmer your region, the more strongly I should suspect that it is the nest of a polistine wasp.

Given more information, we might be able to come up with something more substantial.

Cheers

Jon

Being without knowledge of central American biology, all I can say is that it is a member of the family Vespidae, which includes the Hornets. It is some species of paper wasp, most probably in the genus Polistes. The Vespidae include nearly all social wasps (definitely including those in the photograph), including the various hornets of the Northern hemisphere. (Not counting bees, which are from some pooints of view a subset of the wasps.) The wasps in the picture however,  seem to be fairly clearly in the subfamily Polistinae, wasps that build naked, single-decker paper combs. They are not the only ones to do so, though most of the species that do so are in this subfamily. Polistes species are extremely widespread in the warmer parts of all continents (apart from Antarctica  of course!)

I  cannot argue with the Belizeans of course, but most Polistes are fairly reserved with polite visitors who do not crowd them, though it is a good idea to keep a few metres from their nests and not to move too suddenly. As a rule, by the time they attack they already have expressed their disapproval by turning towards the intruder and limbering their wings ready for use. Away from their nests they tend to be quite docile, but if this species is as virulent as reported, I suppose the locals might understandably be nervous. As I expect never to encounter the species, but have several times been led to skip nimbly when thoughtlessly grabbing or brushing past nests of other species of Polistes or of Belonogaster (without any alarming symptoms, such as throat constriction), I shall accept their assessment with polite reserve. Usually such symptoms suggest hypersensitive victims.

Thanks for the picture,

Jon